Filter or clarification systems have employed a settling assembly to remove impurities from water and/or wastewater for a number of years. In these types of filter systems, tubes or flat plates are commonly used to drastically reduce the footprint of prior clarification systems that merely included an open basin. The tubes or flat plates are commonly mounted at fixed angles to the surface of the liquid to form a plurality of liquid flow channels. The fixed angle of the tubes or plates creates overlapping, horizontally projected surfaces that increases the effective settling surface area compared to an open basin. The increased effective settling surface area is desirable as filtering or clarification capacity is proportional to surface area. The liquid to be filtered is directed through the plurality of liquid flow channels to cause the impurities to settle downwardly at the bottom of a detention basin or sludge collection area. The liquid to be filtered can travel upwardly or downwardly through the plurality of liquid flow channels during the filtration or clarification process.
As the liquid flows upwardly or downwardly through the inclined liquid flow passageways, the impurities settle out of the liquid being filtered. However, over time impurities will build-up on the settling members. The build-up of sludge or other impurities on the settling members is undesirable. For example, the build-up of sludge will reduce the predetermined volume of the fluid flow passageways formed by the settling members which in turn will increase the flow rate of the liquid to be filtered passing through the liquid flow passageways. The increased flow rate will decrease the settling time and, therefore, reduce the efficiency of the clarifier or filter. The build-up of sludge or other impurities must be taken into account when designing the clarifier or filter. For example, the density of the settling members (e.g., settling plates or settling tubes) must be increased to accommodate for the reduction in clarification efficiency. Also, the build-up of sludge on the settling members places restraints on the angle of inclination of the settling members. The lower the angle of inclination of the settling members, the greater the overlap which directly results in a larger effective settling surface area. However, the lower the angle on inclination, the greater the sludge build-up on the settling members. Therefore, prior art designs typically employ an angle of inclination of 55 to 60 degrees. Further, the build-up of sludge on the settling members requires more robust support systems to account for the increased weight on the support system caused by the build-up of sludge on the settling members. This in turn increases the cost and complexity of the clarifier or filter.
EIMCO Water Technologies has developed a plate settler system to address the build-up of sludge on plate settlers. However, this system includes a number of disadvantages not the least of which is that the all of the plates in the plate settler system must be moved from the operational angle of inclination to a vertical position to allow the sludge collected on the inclined plate settlers to descend into the bottom of the basin. The EIMCO design significantly increases the cost and complexity of the clarifier or filter. Also, EIMCO design allows sludge to build-up on the settling plates while the settling plates are oriented in their inclined position. Finally, the EIMCO design will require service interruptions, i.e., to clean the plates, the plates must be moved from their operating position to a vertical position. Notably, even if liquid is allowed to flow through the EIMCO settling plates in the vertical position, the clarification efficiency will be substantially reduced due to the decrease in effective settling area when the settling plates are oriented vertically during cleaning.
Hence, there is a need for a settling system that overcomes the aforementioned disadvantages as well as other disadvantages not articulated above.